edu.wpi.rail.jrosbridge

Class Ros

java.lang.Object

edu.wpi.rail.jrosbridge.Ros

public class Ros
extends Object

The Ros object is the main connection point to the rosbridge server. This object manages all communication to-and-from ROS. Typically, this object is not used on its own. Instead, helper classes, such as Topic, are used.

Version:

April 1, 2014

Author:

Russell Toris - rctoris@wpi.edu

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_HOSTNAME The default hostname used if none is provided.
static int	DEFAULT_PORT The default port used if none is provided.

Constructor Summary

Constructors

Constructor and Description
Ros() Create a connection to ROS with the default hostname and port.
Ros(String hostname) Create a connection to ROS with the given hostname and default port.
Ros(String hostname, int port) Create a connection to ROS with the given hostname and port.
Ros(String hostname, int port, JRosbridge.WebSocketType protocol) Create a connection to ROS with the given hostname and port.

Method Summary

Methods

Modifier and Type	Method and Description
void	addRosHandler(RosHandler handler) Add a handler to this connection.
void	authenticate(String mac, String client, String dest, String rand, int t, String level, int end) Sends an authorization request to the server.
boolean	connect() Attempt to establish a connection to rosbridge.
void	deregisterCallServiceCallback(String serviceName) Deregister a callback for a given incoming service request.
void	deregisterTopicCallback(String topic, TopicCallback cb) Deregister a callback for a given topic.
boolean	disconnect() Disconnect the connection to rosbridge.
String	getHostname() Get the hostname associated with this connection.
int	getPort() Get the port associated with this connection.
JRosbridge.WebSocketType	getProtocol() Get the type of WebSocket protocol being used.
String	getURL() Get the full URL this client is connecting to.
boolean	isConnected() Check if there is a connection to rosbridge.
long	nextId() Get the next unique ID number for this connection.
void	onClose(javax.websocket.Session session) This function is called once a successful disconnection is made.
void	onError(javax.websocket.Session session, Throwable t) This function is called if an error occurs.
void	onMessage(String message) This method is called once an entire message has been read in by the connection from rosbridge.
void	onOpen(javax.websocket.Session session) This function is called once a successful connection is made.
void	registerCallServiceCallback(String serviceName, CallServiceCallback cb) Register a callback for a given incoming service request.
void	registerServiceCallback(String serviceCallId, ServiceCallback cb) Register a callback for a given outgoing service call.
void	registerTopicCallback(String topic, TopicCallback cb) Register a callback for a given topic.
boolean	send(javax.json.JsonObject jsonObject) Send the given JSON object to rosbridge.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_HOSTNAME

public static final String DEFAULT_HOSTNAME

The default hostname used if none is provided.

See Also:

Constant Field Values

DEFAULT_PORT

public static final int DEFAULT_PORT

The default port used if none is provided.

See Also:

Constant Field Values

Constructor Detail

Ros

public Ros()

Create a connection to ROS with the default hostname and port. A call to connect must be made to establish a connection.

Ros

public Ros(String hostname)

Create a connection to ROS with the given hostname and default port. A call to connect must be made to establish a connection. By default, WebSockets is used (as opposed to WSS).

Parameters:

hostname - The hostname to connect to.

Ros

public Ros(String hostname,
   int port)

Create a connection to ROS with the given hostname and port. A call to connect must be made to establish a connection. By default, WebSockets is used (as opposed to WSS).

Parameters:

hostname - The hostname to connect to.

port - The port to connect to.

Ros

public Ros(String hostname,
   int port,
   JRosbridge.WebSocketType protocol)

Create a connection to ROS with the given hostname and port. A call to connect must be made to establish a connection.

Parameters:

hostname - The hostname to connect to.

port - The port to connect to.

protocol - The WebSocket protocol to use.

Method Detail

getHostname

public String getHostname()

Get the hostname associated with this connection.

Returns:

The hostname associated with this connection.

getPort

public int getPort()

Get the port associated with this connection.

Returns:

The port associated with this connection.

getProtocol

public JRosbridge.WebSocketType getProtocol()

Get the type of WebSocket protocol being used.

Returns:

The type of WebSocket protocol being used.

getURL

public String getURL()

Get the full URL this client is connecting to.

Returns:

nextId

public long nextId()

Get the next unique ID number for this connection.

Returns:

The next unique ID number for this connection.

addRosHandler

public void addRosHandler(RosHandler handler)

Add a handler to this connection. This handler is called when the associated events occur.

Parameters:

handler - The handler to add.

connect

public boolean connect()

Attempt to establish a connection to rosbridge. Errors are printed to the error output stream.

Returns:

Returns true if the connection was established successfully and false otherwise.

disconnect

public boolean disconnect()

Disconnect the connection to rosbridge. Errors are printed to the error output stream.

Returns:

Returns true if the disconnection was successful and false otherwise.

isConnected

public boolean isConnected()

Check if there is a connection to rosbridge.

Returns:

If there is a connection to rosbridge.

onOpen

public void onOpen(javax.websocket.Session session)

This function is called once a successful connection is made.

Parameters:

session - The session associated with the connection.

onClose

public void onClose(javax.websocket.Session session)

This function is called once a successful disconnection is made.

Parameters:

session - The session associated with the disconnection.

onError

public void onError(javax.websocket.Session session,
           Throwable t)

This function is called if an error occurs.

Parameters:

session - The session for the error.

session - The session for the error.

onMessage

public void onMessage(String message)

This method is called once an entire message has been read in by the connection from rosbridge. It will parse the incoming JSON and attempt to handle the request appropriately.

Parameters:

message - The incoming JSON message from rosbridge.

send

public boolean send(javax.json.JsonObject jsonObject)

Send the given JSON object to rosbridge.

Parameters:

jsonObject - The JSON object to send to rosbridge.

Returns:

If the sending of the message was successful.

authenticate

public void authenticate(String mac,
                String client,
                String dest,
                String rand,
                int t,
                String level,
                int end)

Sends an authorization request to the server.

Parameters:

mac - The MAC (hash) string given by the trusted source.

client - The IP of the client.

dest - The IP of the destination.

rand - The random string given by the trusted source.

t - The time of the authorization request.

level - The user level as a string given by the client.

end - The end time of the client's session.

registerTopicCallback

public void registerTopicCallback(String topic,
                         TopicCallback cb)

Register a callback for a given topic.

Parameters:

topic - The topic to register this callback with.

cb - The callback that will be called when messages come in for the associated topic.

deregisterTopicCallback

public void deregisterTopicCallback(String topic,
                           TopicCallback cb)

Deregister a callback for a given topic.

Parameters:

topic - The topic associated with the callback.

cb - The callback to remove.

registerServiceCallback

public void registerServiceCallback(String serviceCallId,
                           ServiceCallback cb)

Register a callback for a given outgoing service call.

Parameters:

serviceCallId - The unique ID of the service call.

cb - The callback that will be called when a service response comes back for the associated request.

registerCallServiceCallback

public void registerCallServiceCallback(String serviceName,
                               CallServiceCallback cb)

Register a callback for a given incoming service request.

Parameters:

serviceName - The unique name of the service call.

cb - The callback that will be called when a service request comes in for the associated request.

deregisterCallServiceCallback

public void deregisterCallServiceCallback(String serviceName)

Deregister a callback for a given incoming service request.

Parameters:

serviceName - The unique name of the service call.